Jun 10, 2019

Aircraft Services Co. Storm Water Filtration Challenge


Whether protecting life and property by fighting fires, performing low-impact logging or providing disaster relief and reconstruction efforts around the world, our client has a long history of doing the right thing. Their core values are engineered to ensure employee health and safety and environmental stewardship, which includes:

• Comply with all applicable health, safety and environmental regulations and laws, and global HSE standards;

• Ensure a non-punitive safety environment to encourage reporting of incidents, hazards and safety-related concerns;

• Act to minimize the environmental impact of its activities; and

• Educate and motivate employees and contractors to conduct their activities in a safe and environmentally responsible manner.

Consistent adherence to these values is one of the reasons why our client has received numerous awards for employer excellence from federal aviation authorities.


The Challenge

The facility in question was one of our client’s fleet maintenance and repair facilities. While the facility, at 3.898 acres and 51,000 sq ft might be considered small by some standards, the combination of the fleet’s refueling, chase and service vehicles, and associated fuels and cargo, added complexity to identifying the pollutant source. When scheduled testing at two catch basin compliance points adjacent to the structure showed elevated zinc levels, our client’s legal department contacted CleanWay to order six downspout filtration devices. Because our client’s Environmental Health and Safety department was undergoing restructuring, legal stepped into the research and procurement role.


After competitive analysis, our client selected the downspout filtration system from CleanWay for its high capacity design, plug-and-play installation and ease of maintenance. Each downspout device was fitted with CleanWay’s patented MetalZorb filtration media packs.


“CleanWay recognized the need for rooftop storm water and downspout filtration over 20 years ago,” said Matthew Moulton, general manager of CleanWay Environmental Partners. “As a result, we’ve continuously refined our downspout filtration system, also referred to as roof drain filters, gutter drain filters or rainwater filters, to meet the evolving needs of our customers. Unlike inline options, which require cutting and fitting of the existing downspout, our units are free standing and easily accessible for maintenance and cleaning and incorporate a patented water sampling port for verifiable filtration performance. Two levels of outlet openings allow the unit to be run in either a dry where vector control is a concern or wet configuration to increase removal rates with additional contact time.”


After installation of the downspout filters, zinc levels immediately decreased. The zinc levels at Port II, Basin 3 went from .457 mg/L to below benchmark in late November of 2016. However, levels remained above the 1200-Z permit benchmark at Port I, Basin 1. It is significant to note that testing was being done downstream of the downspout filters at the two catch basins adjacent to the fleet maintenance structure. These two catch basins were the testing compliance points identified in our client’s SWPPP, but with the structural change of added downspout filtration, CleanWay suggested testing at all filtration points. It appeared our client, with CleanWay’s help, was moving toward sustainable compliance when nature intervened.


In December 2016 and much of January 2017, a historic cycle of freezing rain and snow followed by brief thaws hit the area. When the thaw came about in early February 2017, our client’s stormwater facility experienced unprecedented runoff, and dramatically increased zinc levels as tested at the catch basins; 1.734 mg/L at Basin 3 and 1.397 mg/L at Basin 1.


Our client immediately contacted an environmental consulting firm to identify the source of the excessive zinc runoff. On the recommendation of the environmental consulting firm, our client commissioned the coating (by an outside company) of all galvanized roof surfaces (in May 2017); the excavation of collection points for improved sampling; and jetting and scoping of all stormwater facility lines (performed by River City Environmental). CleanWay also “tuned” its downspout filtration media with specially blended filtration packs at each downspout filtration device incorporating MetalZorb media blended with biochar; All of this work was completed in late May of 2017.


The Results

Test results after installation of CleanWay downspout filtration devices and associated facility maintenance was an impressive 0.059mg/L for Port I, Basin 1 and 0.007 for Port II, Basin 3.


Cost Per Square Foot of The Comprehensive Program:

• Initial CleanWay Downspout Install: $0.24 sq ft

• CleanWay Filter & Media Upgrade: $0.10 sq ft

• Power Wash & Roof Painting: $0.49 sq ft

• Excavate Sample Locations: $0.14 sq ft

• Stormwater Pipe Flush: $0.02 sq ft


Total annual O&M cost (CleanWay filters and media) per square foot of roof is an equally impressive $0.10.

CleanWay Environmental Partners Inc.


PO Box 30087

Portland, OR 97294

United States

Phone: 503.280.5102

Fax: 503.288.3658